Composition for lowering the release temperature of phenol- and lower alkyl substituted phenol-blocked isocyanates

ABSTRACT

In the preparation of urethane polymers from phenol- and lower alkyl substituted phenol-blocked isocyanates, it is known to use a variety of reagents such as organotin compounds or amine compounds to lower the temperature at which the isocyanate becomes unblocked or reactive. These compounds, however, cause various side effects such as a decrease in the heat stability of the resultant polyurethane. This invention concerns a novel combination of certain tetravalent organotin compounds and certain quaternary ammonium compounds for addition to a phenolor lower-alkyl substituted phenol-blocked isocyanate system to produce a synergistic lowering of the unblocking temperature in addition to, in the case of a coating compound, providing an unexpected increase in the heat stability of the resultant polyurethane coating.

United States Patent Duncan et a1.

[ June 6, 1972 Filed:

COMPOSITION FOR LOWERING THE RELEASE TEMPERATURE OF PHENOL- AND LOWER ALKYL SUBSTITUTED PHENOL-BLOCKED ISOCYANATES Joe S. Duncan, Mogadore; Otto C. Elmer, Akron, both of Ohio The General Tire & Rubber Company Apr. 17, 1970 Appl. No.: 29,648

Inventors:

Assignee:

U.S. CI ..260/75 NC, 252/182, 260/77.5 NC, 260/77.5 TB, 260/858 Int. Cl. ..C08g 22/34, C09k 3/00 Field of Search ..252/1 82; 260/2.5 AC, 75 NC, 260/77.5 AC, 77.5 TB

References Cited UNITED STATES PATENTS 10/1969 Elmer et al. ..260/22 8/1966 Damusis 5/1967 Schonfeld et al 4/1970 Teaque et a1. ..260/77.5 2/1961 Rudner ..260/268 1 H1961 Elmcr ..260/268 3,150,138 9/1964 Miller ..260/268 3,546,233 12/1970 Szmuszkoniz et a1 ..260/293 OTHER PUBLICATIONS Condensed Chemical Dictionary, 7th Ed., Reinhold, N. Y., 1966, pages 814 and 822- 823.

Primary Examiner-Donald E. Czaja Assistant ExaminerH. S. Cockeram Attorney-Frank C. Rote, Jr.

[5 7] ABSTRACT In the preparation'of urethane polymers from phenoland lower alkyl substituted phenol-blocked isocyanates, it is known to use a variety of reagents such as organotin compounds or amine compounds to lower the temperature at which the isocyanate becomes unblocked or reactive. These compounds, however, cause various side effects such as a decrease in the heat stability of the resultant polyurethane. This invention concerns a novel combination of certain tetravalent organotin compounds and certain quaternary ammonium compounds for addition to a phenol or lower-alkyl substituted phenol-blocked isocyanate system to produce a synergistic lowering ofthe unblocking temperature in addition to, in the case of a coating compound, providing an unexpected increase in the heat stability of the resultant polyurethane coating.

16 Claims, No Drawings COMPOSITION FOR LOWERING THE RELEASE TEMPERATURE OF PHENOL AND LOWER ALKYL SUBSTITUTED PHENOL-BLOCKED ISOCYANATES BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to the field of urethane chemistry. More particularly, this invention concerns phenoland loweralkyl substituted phenol-blocked isocyanates and their utilization in urethane reactions.

2. Description of the Prior Art In the field of urethane chemistry, it is known to use polyisocyanate compounds wherein the NCO groups are temporarily restrained from reaction (U.S. Pat. No. 2,801,990). Generally, the highly reactive NCO groups of the isocyanate will quickly react with compounds containing labile hydrogen atoms (compounds which give a positive Zerewitinoff test*)(*The Zerewitnoff test involves addition of the compound in question to a Grignard solution of methyl iodide; a positive test occurs when the compound decomposes the Grignard reagent to liberate methane gas.) over a wide temperature range to form a polyurethane; by temporarily blocking or masking these reactive NOC groups, isocyanates may be admixed with labile hydrogen containing compounds and the resultant mixture more conveniently handled. This practice is employed where the exigencies of the process or other reaction moieties are such that it is not desirable to have the polyurethane-forming reaction occur immediately upon mixing. For instance, in the field of coatings it is more desirable to pass the substrate to be coated through a bath of coating reactants and then cure the coating at a later stage. Another example would be where a urethane adhesive is used in a flocking operation; obviously it is more desirable to have the adhesive remain unreactive during flocking and then later react or cure to fully bond the flock to the substrate.

In these situations the blocked isocyanate must be capable of being regenerated, i.e., the highly reactive NCO groups must be capable of being unblocked so that they may react with the labile hydrogen atoms to form the polyurethane. As a rule, the blocking agents are compounds that are weakly bonded to the NCO group and are amenable to be dissociated therefrom; the isocyanate may be regenerated or unblocked by merely applying sufficient heat to cause this dissociation. Examples of these dissociatable blocking agents include tertiary alcohols, secondary aromatic amines, mercaptans, lactams, imides, monohydric phenols and others; phenol and lower alkyl substituted (ortho, para, and meta) phenols such as paracresol are by far the most popular of the blocking agents.

Generally, an isocyanate is blocked by treating it with the blocking agent in an inert liquid medium at relatively low temperatures (i.e. C. to 150 C.) and optionally in the presence of a small amount of a catalyst such as a tertiary amine. The recovered product is chemically inert over a wide temperature range and may be mixed with most labile hydrogen-containing compounds without fear of reaction. Admixtures made from these blocked isocyanates may thereafter be made fluid with liquids, granulated with powders, or otherwise compounded and used in a variety of processes such as for dipping, spraying, painting, molding, for a wide range of uses in addition to coatings such as in insecticides, herbicides, and pharmaceuticals.

Blocked isocyanates have rather high release temperatures. For example, I-Iylene MP, a phenol-blocked methylene bis (4- phenyl isocyanate) commercially available from E. I. du Pont de Nemours & Company, has a release temperature of 150 C.; Isonate 123P, a caprolactam-blocked methylene bis (4- phenyl isocyanate) commercially available from Upjohn Company, has an unblocking or release temperature of 138 C.; Mondur S, a phenol-blocked adduct of 2,4-toluene diisocyanate and trimethylol propane, commercially available from Mobay Chemical Company, has an unblocking temperature of 170 C.; and Mondur SH, a cresol-blocked adduct of 2,4- toluene diisocyanate and trimethylol propane and commercially available from Mobay Chemical Company, has an unblocking temperature of 143 C.

These high release temperatures are frequently unmanageable and cause deterioration and degradation of other reaction moieties or process components such as the substrate to which the compound is applied, the flocking material, and so forth, as well as being uneconomical. It has therefore become conventional practice to incorporate into the blocked isocyanate system (i.e. blocked isocyanate and labile hydrogen containing compound) a reagent that will efiectively lower the temperature at which the blocking agent will dissociate. For instance, it is known to incorporate certain amine compounds (U.S. Pat. Nos. 2,916,403 and 3,267,078) and to incorporate certain organotin compounds (U.S. Pat. No. 3,205,201 and Australian complete specification 50757/64) to lower the release temperatures of blocked isocyanates. These reagents, however, produce a number of undesirable side effects. Divalent organotin compounds usually have a short pot or shelf life and lose their unblocking effectiveness after about 24 hours in the blocked isocyanate system so that dip tanks and other containers of these thus treated compounds must be constantly replenished with the organotin compound to retain the proper unblocking temperature. Certain tetravalent organotin compounds, such as dibutyl tin dilaurate, give suffi cient lowering of release temperature but only when high concentrations are used and such high concentrations cause a lowering of the heat stability of the resultant polyurethanes. The general use of tertiary amine compounds has been known to cause serious reductions in the heat stability of the resultant polyurethane. For these and other reasons, a need exists in the art for a compound for use with blocked isocyanates that will not only lower the release temperature but that will have a long effective (pot) life and that will not deteriorate the heat stability or other properties of the resultant polyurethane.

This invention is based on the surprising discovery that certain tetravalent organotin compounds in combination with certain quaternary ammonium compounds in ratios of between about to 20 parts of the former to about 20 to 80 parts of the latter, and in small quantities will produce a synergistic lowering of the release temperature of phenol-or loweralkyl substituted phenol-blocked isocyanates and in addition have a long pot life and further, in coating compounds, cause a serendipitious increase in the heat stability of the cured compound.

Therefore, the main object of this invention is a composition for effectively lowering the release temperature of phenolor lower-alkyl substituted phenol-blocked isocyanates. Other objects include a method of maintaining a low release temperature for phenol-blocked isocyanate reaction systems over a long time period, a method of treating these isocyanate compounds to lower the release temperature thereof in combination with increasing the heat stability of the coatings made therefrom, and a method of obtaining a polyurethane polymer from a phenol or lower-alkyl substituted phenol-blocked isocyanate reaction system that exhibits an acceptable heat stability.

SUMMARY OF THE INVENTION This invention concerns a composition for admixture to a phenolor lower-alkyl substituted phenol-blocked isocyanate reaction system, that is, a phenol-blocked isocyanate in combination with a reaction hydrogen-containing compound and optionally a solvent therefore, for lowering the temperature at which the blocked isocyanate becomes reactive or is released for reaction with the active hydrogens in the other compound to form a polyurethane wherein the compound comprises a mixture by weight of:

a. about 20 to about 80 parts of compound A, which compound conforms to the formula:

1%. wherein R R R an d RIZr? alkyl radicals containing to about 24 carbon atoms, wherein n may be or 1, and wherein m may be 0or l; and

b. about 80 to about 20 parts of compound B, which compound conforms to the formula:

DESCRIPTION OF THE PREFERRED EMBODIMENT Although this invention is directed to phenoland loweralkyl substituted phenol-blocked isocyanates in general, it has particular application to phenol-blocked isocyanates in combination with a wide variety of active hydrogen-containing compounds to form a reaction system for a wide variety of uses such as in coatings, insecticides, herbicides, pharmaceuticals, etc. The preferred embodiment will be limited to a description of the invention in connection with a urethane coating compound such as that known as an ASTM Type 2 coating compound. This type of coating is generally formed from the combination of a blocked isocyanate and a polyester resin in an inert, volatizable liquid carrying medium that, after being applied to a substrate, is subjected to heat to raise the temperature above the release temperature of the blocked isocyanate to release the isocyanate for reaction with the polyester resin to form a polyurethane polymer coating.

The isocyanates that may be blocked for use in this embodi- I ment are virtually any polyisocyanate, especially diand trifunctional isocyanates. Examples of some of these include toluene-2,4-diisocyanate, 1,S-napthalenediisocyanate, cumene-2,4-diisocyanate, 4-methoxy-1,3-phenylenediisocyanate, 4-chloro-l,3-phenylenediisocyanate, 4-bromo-l,3- phenylenediisocyanate, 4-ethoxy-1,3-phenylenediisocyanate, 2,4'-diisocyanatodiphenylether, 5,6-dimethyl-l,3-phenylenediisocyanate, 2,4-dimethyl-1,3-phenylenediisocyanate, 4,4-diisocyanatodiphenylether, 4,6 -dimethyl-1,3-phenylenediisocyanate, 9,IO-anthracenediisocyanate, 4,4-diisocyanatodibenzyl, 3,3'-dimethyl-4,4'diisocyanatodiphenylmethane, 2,6-dimethyl-4,4'-diisocyanatodiphenyl,4,4'-diisocyanatodiphenylmethane, 2,4-diisocyanatostilbene, 3,3- dimethyl 4,4'-diisocyanatodiphenyl, 3,3'-dimethoxy- 4,4- diisocyanatodiphenyl, l,4-anthracenediisocyanate, 2,5- fluorenediisocyanate, 1,8-naphthalenediisocy-anate, 2,6- diisocyanatobenzofuran, and 2,4,6-toluenetriisocyanate. It is to be understood that mixtures of two or more of these polyisocyanates may be employed. These isocyanates may be blocked generally by treating them with a stoichometric amount or less of phenol, preferably in the presence of a small amount of tertiary amine catalyst. Lower alkyl substituted phenols may also be used as blocking agents as they respond similarly to phenol with respect to the compounds of this invention. By lower alkyl substituted phenols" is meant the lower alkyl monoand di-substituted phenols such as the isomeric hydroxy toluenes otherwise known as ortho, para,

and meta cresols. Higher alkyl and more complex substituted phenols do not respond to this invention and are therefore not included in the term lower alkyl substituted phenols".

Among the polyesters usable for reaction with the phenolblocked isocyanates in this invention are those prepared from the condensation of a saturated or unsaturated monoor polycarboxylic acid and a polyhydric alcohol. Examples of suitable polyhydric alcohols include the following: glycerol; pentaerythritol; polypentaerythritol; mannitol; trimethylolpropane; sorbitol; methyltrimethylolmethane; 1,4,6-octanetriol; ethylene glycol, diethylene glycol, propylene glycol, butanediol; pentanediol; hexanediol, dodecanediol; octanediol; chloropentanediol; glycerol monoallyl ether; glycerol monoethyl ether; triethylene glycol; 2-ethylhexanediol-l,4; 3,3'-thiodipropanol; 4,4-sulfonyldihexanol; cyclohexanedioI-l ,4; l ,2,6-hexanetriol; l ,3,5-hexanetriol; polyallyl alcohol; 1,3-bis (Z-hydroxyethoxy) propane; 5,5- dihydroxydiamyl ether; 2,5-dipropanol, tetrahydrofuran-2,5- dipentanol, 2,5-dihydroxytetrahydrofuran; tetrahydropyrrole- 2,5-propanol; 3,4dihydroxytetrahydropyran; 2,5-dihydroxy- 3,4-dihydro-l,2 pyran; 4,4-sulfinyldipropanol; 2,2-bis (4- hydroxyphenyl)-propane; 2,2'-bis (4-hydroxyphenyl)- methane, and the like. These polyesters should have fractional end groups containing labile hydrogen atoms for reaction with the NCO groups in the unblocked isocyanate. These include hydroxyl groups, carboxyl groups, and others.

Examples of polycarboxylic acids include the following: phthalic acid, isophthalic acid; tetrachlorophthalic acid; maleic acid; dodecylmaleic acid; octadecenylmaleic acid; fumaric acid; aconitic acid, itaconic acid, trimellitic acid; tricarballylic acid; 3,3-thiodipropionic acid; 4,4'-sulfonyl-dihexanoic acid; 3-octenedioic-1,8 acid; 3-methyl-3-decenedioic acid; succinic acid; adipic acid; l,4-cyclohexadiene-1,2-dicarboxylic acid; 3- methyl-3,S-cyclohexadiene-1,2-dicarboxylic acid; 8,12- eicosadienedioic acid; 8-vinyl-l0-octadecenedioic acid; and the corresponding acid anhydrides, acid chlorides, and acid esters such as phthalic anhydn'de, phthaloyl chloride, and the dimethyl ester of phthalic acid.

The polyester and the phenol or lower alkyl substituted phenol-blocked isocyanate are generally admixed together in an inert volatizable solvent such as methyl ethyl ketone or xylene, the solution applied to the substrate, and then heated to volatilize the solvent and unblock the isocyanate. Examples of other solvents usable herein are those that do not react with either the blocked isocyanate moiety or the polyester and other reaction system moieties and include acetone, methyl isobutyl ketone, cyclohexanone, ethyl ether, tetra hydrofuran, ethyl acetate, isopropyl acetate, n-butyl acetate, methyl Cellosolve acetate, amyl acetate, ethylene glycol diacetate, ethyl lactate, methyl Cellosolve, butyl Cellosolve, benzene, toluene, naphtha, turpentine, ethylene dichloride, carbon tetrachloride, trichloroethylene, carbon disulphide, and pyridine.

The substrates that may be coated with this mixture include non-metals such as rubber, plastic, cement, fabric, wood, etc. and metals such as aluminum, brass, copper, iron, steel, etc. The application may be made by any of the conventional means such as spraying, brushing, roll coating, dipping, etc. All of these are fully contemplated herein.

One portion of the composition of this invention is herein denoted as compound A and may be defined as a tetravalent organotin compound conforming to the following general formula:

wherein R R R and R are alkyl radicals containing one to about 24 carbon atoms and wherein n may be 0 or 1 and m may be 0 or 1. Specifically excluded from this formula are lOlO39 0743 trivalent and divalent organotin compounds for they have not um phthalimidate and has the following formula: been found to exhibit any of the synergistic properties disclosed herein when placed in combination with the later described quaternary ammonium compounds. The alkyl radicals in the compound may be any of those containing one to about 24 carbon atoms such as methyl, ethyl, butyl, propyl, 1 pentyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, CH3 J tetradecyl, pentadecyl, hexadecyl, heptadecyl octadecyl, l nonadecyl, eicosyl, heneicosyl, docosyl, tricosyl, and I; tetracosyl and variations thereof. of, alkyl Where utilized in the form of the carboxylic acid, the alkyl m radical or radicals may form the backbone of the acid radical. It is to be understood that these different types of compounds The acids may be mono, di, or tri carboxylic; a dicarboxylic may be mixed together for use in this invention.

acid may then attach to the tin via the carboxyl radical at n The presence of the anion portion of compound B is to soluand m so that R and R become one and the same molecule. bilize the compound in the solvent of the coating compound, Examples of acids that could be used for this purpose include i.e. the solvent containing the blocked isocyanate and the malonic acid, succinic acid, glutaric acid, adipic acid, pimelic polyester. For this reason, radicals R R R and R are well acid, suberic acid, azelaicacid, sebacic acid, maleic acid, and. asthe anions are to be kept at a molecular size less than about 24 carbon atoms to insure complete solubilization of the compound in the solvent. Above 24 carbon atoms compound B so forth. The tricarboxylic acid may attach to the tin at three places so that R R and R become one and the same molecule. Examples of acids that could be used for this purdoes not fully dissolve in the coating compound and begins to pose include tricarballylic acid and citric acid. Examples of precipitate onto the substrate which not only has a deterioratmonocarboxylic acids that may be used (to incorporate R R ing influence upon the degree of adhesive of the coating to the and/or R include acetic acid, butyric acid, caproic acid, cap- 5 substrate but does not cause a sufiicient reduction in the unrylic acid, capric acid, lauric acid, myristic acid, palmitic acid, blocking temperature. Further examples of quaternary amstearic acid, arachidic acid, and so forth. monium compounds useful as compound B in this invention Specific examples of the tetravalent tin compounds of this include hexadecyl trimethyl ammonium stearate, and invention include dibutyl tin dilaurate, dibutyl tin diacetate, dimethyldibenzyl ammonium stearate. dibutyl tin maleate, and tributyl tin acetate. Note that a fully Many of these compounds are commercially available; for alkylated tetravalent tin compound does not fit the above forinstance, alkyl dimethyl benzyl ammonium phthalimidate and mula and is not within the metes and bounds of this invention; alkyl dimethyl benzyl ammonium saccharinate are commer' as will be shown later in the examples, this latter form of orcially available from Onyx Chemical Company, Division of ganotin compound (such as tetrabutyl tin) does not achieve Millmaster Onyx Corporation, and hexadecyl trimethyl amthe same results as does the compounds of this invention. monium stearate, tetraethyl ammonium benzoate and Many of these tetravalent organotin compounds of this inventetraethyl ammonium acetate are commercially available from tlun are commercially uvailahle; for instance. dibutyl tin dilau' Eastman Organic Chemicals Company. These compounds rule is commercially available from the Union Carbide Chemimay also be easily prepared in the laboratory. cul Company and dibutyl tin diacetalc and dibutyl tin muleate For instance, for the preparation of dimethyl dibenzyl umare commercially available from M & T Chemicals lncor- 40 monium stearate, one dissolves 0.02 moles of sodium stearate poratedin 22 moles of water and adds 5 moles of chloroform along The other portion of the composition of this invention is with 0.02 moles of dibenzyl dimethyl ammonium chloride and herein denoted as compound B and may be defined as a then refluxes that mixture for 1 hour. About 5 moles of quaternary ammonium compound conforming to the followethanol is then added and refluxing resumed for another 4 ing general formula: hours at about 55 C. Thereafter the chloroform layer is distilled off and extracted with toluene; the toluene solution is R5 dried and stripped under vacuum to yield 0.02 moles of solid l1+ dimethyl dibenzyl ammonium stearate. Preparation of other R7 compounds may be accomplished in a similar manner and are fully within the ambit of one skilled in the chemical art.

The basis of this invention is that the combination of these wherein R R,;, R-,, and R are organic radicals containing one two compounds produces a synergistic lowering of the release to about 24 carbon atoms and selected from the group consisttemperature of the phenolor lower-alkyl substituted phenoling of alkyl'radicals and aralkyl radicals and wherein Z is an blocked isocyanate and an unexpected increase in the heat anion selected from the group consisting of ortho diacid imide stability of the polyurethane produced therefrom in the form anions, aliphatic carboxylic anions, and aromatic carboxylic of a coating. These materials may be used in a range of from acid anions all containing from one to about 24 carbon atoms. about 20 to 80 parts by weight of Compound A to 80 to about Examples of the quaternary ammonium compounds con- 20 parts by weight of compound B and preferably 50 parts of taining ortho diacid imide anions include those of the mixed the former to 50 parts of the latter, i.e. in an equal ratio. The diacid. imide type such as alkyl dimethyl benzyl ammonium 6 combined amounts of these materials are effective in achievsaccharinate (an o-sulphobenzoic acid imide) where the alkyl ing the aforedescn'bed results when used in amounts as minute radical contains a statistical mixture of C to C alkyl radicals as 1 part by weight per 100 parts of the phenol-blocked isoand has the following formula: cyanate moiety to as high as 5 parts and higher. The efficiency of the combination begins to drop off rather sharply below about 1 part whereas above about 5 parts the heat stability of 1 U the resultant polyurethane begins to suffer; in addition, the added material cost above about 5 parts begins to become significant. CH3 E As an example of the lowering of the release temperature, a g mixture of a polyester resin and a phenol-blocked isocyanate, H the latter having a release temperature of 170 C., will in the 0g alkyl 0 presence of 1.72 parts by weight of alkyl (C C average) W W dimethyl benzyl ammonium saccharinate (per parts of Another example is that of the ortho (homogeneous) diacid isocyanate) exhibit a release temperature of C. and in the imide type such as alkyl (C C dimethyl benzyl ammoni- 75 presence of 1.72 parts by weight of dibutyl tin maleate exhibit a release temperature of 120 yet when 0.86 parts f each isocyanate composition with an admixture of the above-disof these reagents are added thereto, the release temperature closed compounds A and B of this invention in their disclosed drops to 1 10 C. In this same example the heat stability of the ratios and arnounts.

resultant polyurethane with 1.72 parts of dibutyl tin maleate is 15 hours at 120 C., the heat stability of the resultant polyurethane with the 0.86 parts of each of these reagents was greater than 148 hours. Therefore, it is readily seen that this invention does produce both a synergistic lowering of the release temperature and an unexpected increase in the heat stability of the cured polymer.

Following are examples given to show one skilled in the art an indication of how to practice the invention as well as to point out certain highlights in specific compounds within the general definition of compounds A and B. Unless otherwise noted, all parts are parts by weight and all percentages are percentages by weight.

For the purpose of the following examples, the unblocking EXAMPLE 1 or release temperature of the phenol-blocked isocyanate was determined by the following procedure. A strip of aluminum A phenol-blocked isocyanate-polyester resin coating comfoil about 1 inch by 6 inches long was placed on the top of a pound was prepared from the ingredients listed below in Table temperature gradient melting point bar such as a Kofler Hot 1 by admixing them in the solvent until a smooth blend of Bank. The aluminum strip was then marked with a pencil in about 25 centipoise viscosity was obtained. The release tem- 10 C; intervals from 80 C. to 200 C. A drop of the liquid perature of this compound was found to be 170 C. comprising the phenol-blocked isocyanate, the polyester Y resin, and various compounds of this invention was placed at each of these marks on the melting point bar and heated for 15 V 1 minutes. Thereafter the strip (containing the drops) was placed in an acetone bath for 5 minutes. The acetone dissolved away the unpolymerized material. The lowest tempera- Mondur 5 7 246.35 parts ture marking on the strip at which a drop or portion thereof Ethylene butylene adipate 360.00 parts d 3 t polyester (2000 mw) remt unle was akenlas being the release temperature of that Park) 125, 4.00 Pam pm m "mnpuum Methyl ethyl ketone solvent 798.65 parts Total: 1409.00 parts The heat stability of the polymerized material was deter- 3o mined as follows: Samples of the above-described liquid were brushed coated onto glass slides and heated in an air circu- 'phenol-blocked triisocyanate, Mobay Chemical Company lated oven at 120 C. until fully cured as evidenced by the hl ri natural r. Hercules P w mp ny achievement of a maximum Sward Rocker Hardness value of the coating that was determined by using a Sward Hardness Rocker Tester, Model C, No. 1697, made by the Gardner EXAMPLE-2 Laboratories Incorporated, Bethesda, Maryland, which testing procedure is described in "Physical and Chemical Examination, Paints, varnishes, Lacquers, and Colors, Gardner & Sward, published by Gardner Laboratories, 1962, page 138. These films are then held at 120 C. until degradation of the polymers was evidenced by a reduction of one point in the Sward Rocker Hardness value.

A number of compounds corresponding to the formula of compound B, listed below in Table 2A, were admixed with dibuyl tin dilaurate, which corresponds to the formula of compound A, in various ratios and these combinations physically blended with portions of the phenol-blocked isocyanate polyester resin coating compound of Example 1. The release 4 temperatures of the phenol-blocked isocyanate and the heat By incorporating this invention into existing phenoland Stabililies 0f the resultant Polyurethane comings w lower-alkyl substituted phenol-blocked isocyanate systems mined for each Sample y the Prcmedures described earner there is opened up a number of new uses and new applications and are listed below Table for urethane-based materials. For instance, certain phar- 5O maceuticals and insecticides that contain heat sensitive com- TABLE 2 pounds may now be made since the incorporation of this invention permits the isocyanate to be unblocked at a lower Compound B temperature and in addition, the compounds produced in this Alkyl dimethyl benzyl ammonium saccharinate reaction have a greater storage life. Further, utilization of this 5 5 ADBAS invention permits the establishment of urethane based Alkyl dimethyl benzyl ammonium phthallmidate coatmgs and adhesives in environments heretofore restricted ADBAP because of the low heat stablhty. of the w Hexadecyl trimethyl ammonium stearate HTAS Dimethyl dibenzyl ammonium stearate DBAS In addition, the art is now provided with a new process for Tetraethyl ammonium benzoate =TEAB lowering the release temperature of phenol-blocked iso- Tetraethyl ammonium acetate=TEAA cyanate compounds and simultaneously increasing the heat CompoundA stability of the reaction product thereover mainly by treating Dibutyl tin dilaurate =DTD the phenol-blocked or lower alkyl substituted phenol-blocked flmixturegf p i V V r TABLE 213 Sample 1 2 3 4 5 6 7 B 9 10 11 Mondur S in coating compound (parts) 100 ADBAS (parts) 1.43 ADBAP (parts) HTAS (parts) D AS (parts) TEAB (parts) TEAA (partsL. D'ID (putts) .4 Release temperature C .7 120 120 110 120 110 100 100 Heat stability (hours). 148 so 9 0 5 48 8 Sample 12 13 14 15 l6 17 18 ll] 20 Zl 22 Mondur S in coating compound (parts) ADBAS (parts) ADBAP (parts)- HTAS (parts)- DBAS (parts)- 'IEAB (parts). TEAA (parts). DID (parts) Release temperature C.) Heat stability (hours) t Sample Mondur S In coating compound (parts) ADBAS (ports) ADIlAl (pnrts) t H r ll'lAl-l (ports) DHAH (pultu)v 'lJilA ll (parts). 'IEAA (pm-ts D'Il) (ports)- 0.21) Release tempera 110 100 100 100 100 100 Heat stability (hours) 148 148 148 148 16 13 Sample 34 35 36 37 38 30 40 41 42 43 Mondur S in ctopting compound (parts) 100 100 100 100 100 100 100 This example shows that whereas separately treating the responds to the formula of compound B, in various ratios and phenol-blocked isocyanate polyester coating compound with these admixtures blended with portions of the phenol-blocked compounds corresponding to the formula of compound B and 40 isocyanate polyester resin coating compound of Example 1. with compounds corresponding to the formula of compound The release temperatures of the blocked-isocyanate and the A lowers the release temperature, treating the same coating heat stabilities of the resultant polyurethane coatings were compound with a combination of compounds A and 8 prodetermined for each sample by the procedures described earlivides a synergistic lowering of the release temperature below er and are listed below in Table 3B. that of either compound alone. In addition, this example 45 shows that the combination of compounds A and B increases TABLE 3A the heat stability of the resultant polyurethane coating, at the Compound A lowered release temperature, beyond the heat stability when Dibutyl tin diacetate =DBTDA compound A was used alone. Dibutyl tin maleate DBTM EXAMPLE 3 5o Tributyl tin acetate =TBTA Compound B A number of compounds corresponding to the formula of Alkyl dimethyl benzyl ammonium saccharinate compound A, listed below in Table 3A, were admixed with ADBAS alkyl dimethyl benzyl ammonium saccharinate, which cor- "gml f ll lfl TABLE 3B Sample 1 2 3 4 5 6 7 8 9 1O 11 Mondur S in coating compound (parts) 100 100 100 100 100 100 100 100 100 100 DBTDA (parts).

Sample 12 13 14 16 16 17 l8 19 20 21 22 Mondur S in coating compound (parts) t 100 100 100 100 100 100 100 100 100 100 100 DBTDA (parts) Release temporal: Heat stability (hours) 3 ,668, 1 86 ll 12 EXAMPLE 4 I wherein R R R and R,, are organic radicals containing one to about 24 carbon atoms and are selected from the group consisting of alkyl radicals and aralkyl radicals, wherein Z is r i an anion selected from the group consisting of ortho diacid 2:1 3: s g f t i fs fig gglzggiz g igz igzz gg gj 5 imide anions, aliphatic carboxylic acid anions, and aromatic mres blended with portions of the phenol blocked isocyanate carboxylic acid anions containing from about one to about 24 polyester resin coating compound of Example 1. The release carbonhatoins d A d d B ht temperatures (as a function of time) and the heat stabilities of w .erem a g t 3 a g the resultant polyurethane coatings were determined for each who varying mm a to a on w sample by the procedures described earlier and are listed compound A and compound B are present m a rota A number of compounds that do not correspond to the formula of compound A listed below in Table 4A, were admixed below in Table amount varying from about I to about 5 parts; and,

d. about 100 parts of a phenol-blocked isocyanate. TABLE 4A 2. The composition of claim 1 wherein Compound A is Com unds dibutyl tin dilaurate and compound B is alkyl dimethyl benzyl Teffabutyl fin=TBT ammonium saccharinate wherein said alkyl is comprised of a Tributyl tin chloride TBTCl x? i Cw adicals- Stannous octoate: 5 O 3. The composition of claim 1 wherein compound B is alkyl stannous 1 =5 o dimethyl benzyl ammonium phthalimidate wherein said alkyl St li l u is comprised of a mixture of C to C radicals. Compound B 4. The composition of claim 1 wherein compound B is hex- Alkyl m dimeth l b l ammonium Saccharinate (A1} adecyl trimethyl ammonium stearate.

HAS) 5. The composition of claim 1 wherein compound B is mixture of C C dimethyl dibenzyl ammonium stearate.

TABLE 413 Sample 1 2 3 4 5 ii 7 8 l) 10 11 Momlur H in muting compound (put-ts) H10 100 100 l()() 100 100 lOll 100 I00 I00 100 lll'l l uu'ifll 1.72 1.43 l. M lLKll ll 'll I (pm-Iii) H HUN. (putts) H Olu (parts) S Lin (puris). ADBAS (purts) i.. Release temp. lst day C.) Release temp. 2nd day C. Release temp. 4th day C.) Heat stability (hours) Sample 12 13 14 15 16 v17 18 19 20 21 Mondur S in coating compound (parts) TB'I (parts) ADBAS (parts) Release temp. 1st day C.) Release temp. 2nd day C.) Release temp. 4th day C.)

Heat stability (hours) This example shows that combinations of compounds no? 6. The composition of claim 1 wherein compound B is corresponding to the formula of compound A and compounds tetraethyl ammonium acetate. that do correspond to the formula of compound B do not 7. The composition of claim 1 wherein compound B is synergistically reduce the release temperature of the phenoltetraethyl ammonium benzoate. blocked isocyanate and that combinations of divalent tin com- 8. The composition of claim 1 wherein compound A is dibupounds and compounds corresponding to the formula of comtyl tin diacetate. pound B do not have an effective shelf or pot life. 9. The composition of claim 1 wherein compound A is dibu- What is claimed is: tyl tin maleate. 1. Acomposition comprisingamixture of: 10. The composition of claim 1 wherein compound A is a. compound A which is a tetravalent tin compound contributyl tin acetate.

forming to the following formula: 11, The composition of claim 1 wherein the ratio of compound A to compound 13 is about 1 to l by weight. 0 R! O 12. The composition of claim 1 wherein said phenoll blocked isocyanate comprises a lower alkyl substituted phenol-blocked isocyanate. (B 13. A composition which is curable to an elastomeric coating, having improved heat stability, by heating at about 1' l00-l40 C. for about 15 minutes, said composition compris- H ing a mixture of a polyester resin, a phenol-blocked isocyanate wherein R R R and R are alkyl radicals containing one to and a composition comprising: about 24 carbon atoms, wherein n may be 0 or 1, and wherein a. compound A which is a tetravalent tin compound cony be 0 forming to the following formula:

b. compound B which is a quaternary ammonium comd f to the followin form la: 0 R1 0 poun con ormmg g u Y H Q} 2-[ ]un[ ]m-R4 Ra Rs 0 p 2- (i=0 R1 R3 I ia nun-1n --u wherein R R R and R are alkyl radicals containing one to about 24 carbon atoms, wherein n may be or 1 and wherein .mmaybeOor l;

b. compound B which is a quaternary ammonium compound confonning to the following formula:

wherein R R R-,, and R are organic radicals containing one to about 24 carbon atoms and are selected from the group consisting of alkyl radicals and aralkyl radicals, wherein Z is an anion selected from the group consisting of ortho diacid imide anions, aliphatic carboxylic acid anions, and aromatic carboxylic acid anions, containing from one to about 24 carbon atoms; and,

c. wherein compound A and compound B are in a weight ratio varying from about 1:4 to about 4:1 and wherein compound A and compound B are present in a total amount varying from about 1 to about 5 parts per 100 parts of said phenol-blocked isocyanate.

14. A process for producing a cured elastomeric coating comprising heating at about 100l40 C. for about minutes a composition comprising a polyester resin, a phenolblocked isocyanate, and composition comprising:

a. compound A which is a tetravalent tin compound conforming to the following formula:

wherein R R R and R are alkyl radicals containing one to about 24 carbon atoms, wherein n may be 0 or 1, and wherein m may be 0 or 1;

b. compound B which is a quaternary ammonium compound confonning to the following formula:

wherein R R R and R are organic radicals containing one to about 24 carbon atoms and are selected from the group consisting of alkyl radicals and aralkyl radicals, wherein Z is an anion selected from the group consisting of ortho diacid L imide anions, aliphatic carboxylic acid anions, and aromatic carboxylic acid anions, containing from one to about 24 carbon atoms; and,

c. wherein compound A and compound B are present in a weight ratio varying from about 1:4 to about 4:1.

15. A process for producing a cured adhesive comprising heating at about 100140 C. for about 15 minutes a composition comprising a polyester resin, a phenol-blocked isocyanate, and composition comprising:

a. compound A which is a tetravalent tin compound conforming to the following formula:

wherein R R R and R. are alkyl radicals containing one to about 24 carbon atoms, wherein n may be 0 or 1, and wherein m may be 0 or 1;

b. compound B which is a quaternary ammonium com- 15 pound conforming to the following formula:

wherein R R R and R are organic radicals containing one to about 24 carbon atoms and are selected from the group consisting of alkyl radicals and aralkyl radicals, wherein Z is an anion selected from the group consisting of ortho diacid imide anions, aliphatic carboxylic acid anions, and aromatic carboxylic acid anions, containing from one to about 24 carbon atoms; and,

c. wherein compound A and compound B are present in a weight ratio varying from about 1:4 to about 4:1. 16. A composition comprising a mixture of: a. compound A which is a tetravalent tin compound confomiing to the following formula:

wherein R R R and R are organic radicals containing one to about 24 carbon atoms and are selected from the group consisting of alkyl radicals and aralkyl radicals, wherein Z is an anion selected from the group consisting of ortho diacid imide anions, aliphatic carboxylic acid anions, and aromatic carboxylic acid anions containing from one to about 24 carbon atoms; and,

c, wherein compound A and compound B are in a weight ratio varying from about 1:4 to about 4: 1.

Anna

UN TED STATES PATENT ()FFXCE CERTIFICATE OF (IQR'RECTKQN Patent No. 3 668 l86 Dated Juno, 6, 1972 Invcntor(s) Duncan ct nl It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Cn-Lumu-i, line 2 L, "NOC" should read NCO mi Column 2 line 68, "reaction" should read reactive Column 3, lines 7 and 8, the phrase "containing to about 2 carbon atoms should read containing 1 to about 2 carbon atoms Column 3 line 27, the phrase "l or about" should read 1 to about Column 6, line 5, the formula O r H should read C M n W C kyl' Y Y N+ CH alkyl Column 6, line 17, "are" should read as Column 8, Table 2B "Mondur S in coating compound (parts) 100 100 100 lOO 104 should read Mondur S in coating compound (parts) 100 100 100 100 100 L. Signed and sealed this 12th day of December 1972.

(SEAL) Attest:

EDWARD M.FLETCIIER JR. i A u G of ROBERT GOTTSCHALK $5.111 f1ce1 Commissioner of Patents UNITED STATES PATENT QFFXCE CERTKFICATE OF CORREC-Tl-QN Patent No. 3,668,186 Dated n June 6L1? Invcntofls) Duncan 0t (L1 It is certified that error appears in the above-identified patent andthat said Letters Patent are hereby corrected as shown below:

En-Ami, line 2-3, "NOC" should read M NCO mi Column 2 line 68, "reaction" should read reactive Column 3, lines 7 and 8, the phrase "containing to about 2% carbon atoms" should read I containing 1 to about 2 4 carbon atoms Column 3 line 27, the phrase "l or about" should read l to about Column 6, line 5, the formula O N should read C F a --N .I H Cth h g v I A y CH loa fi c O a kyl' /lN+ CH lalkyl Column 6, line l7, "are" should read as Column 8, Table 2B, Mondur S in coating compound (parts) 100 100 100 .100 10. should read Mondur S in coating compound (parts) 100 100 100 109 100 L. Signed and sealed this 12th day of December 1972. J

(SEAL) Attest:

EDWARD M.FLETCIIER,JR. t A ttesting Officer ROBERT GOTTSCHALK Commissioner of Patents 

2. The composition of claim 1 wherein Compound A is dibutyl tin dilaurate and compound B is alkyl dimethyl benzyl ammonium saccharinate wherein said alkyl is comprised of a mixture of C11 to C18 radicals.
 3. The composition of claim 1 wherein compound B is alkyl dimethyl benzyl ammonium phthalimidate wherein said alkyl is comprised of a mixture of C11 to C18 radicals.
 4. The composition of claim 1 wherein compound B is hexadecyl trimethyl ammonium stearate.
 5. The composition of claim 1 wherein compound B is dimethyl dibenzyl ammonium stearate.
 6. The composition of claim 1 wherein compound B is tetraethyl ammonium acetate.
 7. The composition of claim 1 wherein compound B is tetraethyl ammonium benzoate.
 8. The composition of claim 1 wherein compound A is dibutyl tin diacetate.
 9. The composition of claim 1 wherein compound A is dibutyl tin maleate.
 10. The composition of claim 1 wherein compound A is tributyl tin acetate.
 11. The composition of claim 1 wherein the ratio of compound A to compound B is about 1 to 1 by weight.
 12. The composition of claim 1 wherein said phenol-blocked isocyanate comprises a lower alkyl substituted phenol-blocked isocyanate.
 13. A composition which is curable to an elastomeric coating, having improved heat stability, by heating at about 100*-140* C. for about 15 minutes, said composition comprising a mixture of a polyester resin, a phenol-blocked isocyanate and a composition comprising: a. compound A which is a tetRavalent tin compound conforming to the following formula:
 14. A process for producing a cured elastomeric coating comprising heating at about 100*-140* C. for about 15 minutes a composition comprising a polyester resin, a phenol-blocked isocyanate, and composition comprising: a. compound A which is a tetravalent tin compound conforming to the following formula:
 15. A process for producing a cured adhesive comprising heating at about 100*-140* C. for about 15 minutes a composition comprising a polyester resin, a phenol-blocked isocyanate, and composition comprising: a. compound A which is a tetravalent tin compound conforming to the following formula:
 16. A composition comprising a mixture of: a. compound A which is a tetravalent tin compound conforming to the following formula: 